Zigzag-rule joint.



H. P. RICHARDS.

ZIGZAG RULE JOINT.

APPLICATION r1121) 001. 1, 1911.

- 1,02 ,3 7, Patented May 14,1912.

Illl

v I fiPfi'g d W M12";

UNITED STATES PATENT OFFICE.

HUBERT P. RICHARDS, OF NEW BRITAIN, CONNECTICUT, ASSIGNOR TO THE STANLEY RULE AND LEVEL COMPANY, OF NEW BRITAIN, CONNECTICUT, .A. CORPORATION OF CONNECTICUT.

ZIGZAG-RULE JOINT.

Specification of Letters Patent.

Application filed October 7, 1911.

Patented May 14, 1912.

Serial No. 653,335.

To all whom it may concern Be it known that I, IIUBERT P. RICHARDS, a citizen of the United States, residing at New Britain, Hartford county, State of Connecticut, have invented certain new and useful Improvements in Zigzag-Rule Joints, of which the following is a full, clear, and exact description.

My invention relates to an improved joint for a folding rule.

The type of folding rule to which this invention relates is a rule in which the several sections thereof are made up of two or more flat strips, with their ends overlapping. The bearing is made up of plates which have a relatively broad surface engagement, one plate being secured near one end of one rule section, the other plate being secured near one end of the other rule section. A pivot passes through said plates and there is also provided means for frictionally holding said plates in such position as to hold the sections of the rule extended and folded.

The particular object of the present invention is to provide a locking means for the plates, whereby endwise movement of said plates on the rule sections is prevented.

In the drawings, Figure 1 is an edge elevation relatively enlarged, of two connected ends of two rule sections. Fig. 2 is a plan view of one section. Fig. 3 is a detail view. Fig. 4 is a section on the line w-w, Fig. 3. Fig. 5 is a detail in section enlarged.

A description in detail of one of the hearing plates will be sufficient, as both plates may be similarly constructed, so far as concerns the present invention.

In Figs. 3 and 4, I have shown a plate detached, the main body of said plate being indicated at 1. 22 are side flanges which engage and clamp around the side edges of a rule section 3. WVhen the plate is in place, the side flanges 2-2 are turned in. t4 represent perforations in the plate. The material struck down in forming each of these perforations is caused to form a relatively sharp edged annular fastening projection 5. When the parts are assembled, these sharp projections are embedded in the wood of the rule section 2 so as to securely hold the plate 1 from sliding endwise thereon. I am aware that heretofore thin straight prongs have been provided for this purpose, but such devices are easily and frequently bent down and rendered useless when the plate is being forced into place. Again, where a narrow thin prong is used, it is necessary, in order to avoid, so far as possible, the bending of the prong, to cause said prong to extend lengthwise with the grain of the wood. By reason of this fact, the narrow prong offers very little resistance to end movement.

By the present invention, the interlocking device being annular in form is of the strongest possible construction, hence, when the plate is forced into tight contact with the wood of the rule section, it cannot be deflected or bent, but cuts its way in with certainty to such an extent as to lock the plate -1 positively in place against end movement.

Particularly is this true since some part of each projection is sure to cross the grain of the wood.

WVhat I claim is:

In a folding rule of the character described two flat wood sections the flat surfaces of which overlap, a foldable joint arranged between and connecting the overlapping portions of said sections, said joint including a metallic plate, flanges along the side edges of said plate, said flanges being bent to tightly embrace the rule section adacent thereto, and a locking projection extending from the inner surface of said plate and projecting into said wood section and across the grain thereof, said locking projection being in the form of an annular flange open at the center.

HUBERT P. RICHARDS.

Witnesses:

H. S. WALTER, W. J. WVoRAM.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, 

